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2 years ago

Tell whether the ratios form a proportion. 1/3, 7/21

Mathematics

2 answers:

Mandarinka [93]2 years ago

7 0

Answer:

i would say yes

my work :

so i did 21 times 1 which is 21.

Tben i did 3 times 7 which is also 21.

So in conclusion i would say yes but i can't guarantee that

Anuta_ua [19.1K]2 years ago

6 0

Answer:

Yes

Step-by-step explanation:

7/21 -> Divide both sides by 7 which gets you 1/3

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Among the four northwestern states, Washington has 51% of the total population, Oregon has 30%, Idaho has 11%, and Montana has 8

morpeh [17]

Answer:

Step-by-step explanation:

H₀ : The distribution of the sample agrees with the population distribution.

H₁ : the distribution of the does not agree with the population distribution.

Using the Chi-square test statistics

we will compute the expected frequencies

Now expected frequency for Washington will be

Fe = Npi = 1000×51% = 5100

expected frequency for Oregon

Fe = Npi = 1000×30% = 300

expected frequency for Idaho

Fe = Npi = 1000×11% = 110

expected frequency for Montana

Fe = Npi = 1000×8% = 80

The Chi=square test statistics is;

x² = ∑ [ (Fo - Fe)² / Fe )

now we substitute

Given our Fo ( 450 in Washington, 340 in Oregon, 150 in Idaho, and 60 in Montana) from the question

x² = (450-510)²/510 + (340-300)²/300 + (150-110)²/110 + (60-80)²/80

x²= 31.9376

so the chi-square test statistics is 31.9376

Now the chi-square critical value

first we compute for degree of freedom

d.f = k -1 = 4 - 1 = 3

So from the critical value table, degree of freedom 3 and significance level 0.05,

the chi-square critical value is 7.8147

Therefore chi-square test statistics 31.9376 is greater than the chi-square critical value 7.8147, so NULL HYPOTHESIS IS REJECTED at 5% significance.

There is sufficient evidence to warrant rejection of the claim that the distribution of the sample agrees with the distribution of the state populations.

3 0

3 years ago

The future value of a certain money market account with a fixed interest rate of

rosijanka [135]

Answer:

D = $8637.45

Step-by-step explanation:

Rate = 3.65% = 0.0365

Principal = 5000

Time (t) = 15 years

N = 12 (since its compounded monthly)

Compound interest (A) = P(1 + r/n)^nt

A = 5000(1 + 0.0365 / 12)^15*12

A = 5000(1 + 0.00304)¹⁸⁰

A = 5000(1.00304)¹⁸⁰

A = 5000 * 1.7269

A = 8634.86

The investment would worth $8634.86

Note: the final answer may vary slightly from the answer in the options due to ± from approximation

3 0

2 years ago

Seven times a number decreased by three-fourths of the same number is 25. What is the number?

Tomtit [17]

Answer:

103/28

Step-by-step explanation:

Let the number be 'x'

Equation:-

7x - 3/4 = 25

7x = 25 + 3/4

7x = 100/4 + 3/4

7x = 103/4

x = 103/(4 x 7)

x = 103/28

5 0

3 years ago

Read 2 more answers

If the sum of four consecutive numbers is 854, what is the third one?

lukranit [14]

Answer:

214

Step-by-step explanation:

The set up would be x + (x + 1) + (x + 2) + (x + 3) = 854, naturally as the numbers are consecutive. Solving for x:

x + (x + 1) + (x + 2) + (x + 3) = 854,

x + x + 1 + x + 2 + x + 3 = 854,

4x + 1 + 2 + 3 = 854,

4x + 6 = 854,

4x = 854 - 6 = 848,

x = 848/4 = 212

The third number then should be 212 + 2 = 214

7 0

3 years ago

Convert the exponential function to the form indicated. (Round all coefficients to four significant digits.) f(x) = 2.5 e^(-0.7

Jobisdone [24]

$f(x)=2.5e^{-0.7x}=2.5\left(e^{-0.7}\right)^x\\\\A=2.5\\\\b=e^{-0.7}$

5 0

3 years ago